1. Technical Field
This disclosure relates generally to paper feeders and more particularly to a paper feeder used for manual paper feed in image forming apparatuses such as copiers, printers, and facsimile machines.
2. Description of the Related Art
Some image forming apparatuses such as copiers have an automatic paper feed unit and a manual paper feed unit including a manual paper feed tray provided to a manual paper feed opening. In the automatic paper feed unit, a stack of paper sheets is set in one or multiple paper feed cassettes disposed in the main body of the image forming apparatus (the apparatus main body), and the uppermost one of the paper sheets is fed out based on a command. The manual paper feed unit is used to form an image on a paper sheet of a type or size that is not set in the paper feed cassettes of the automatic paper feed unit.
Some conventional image forming apparatuses employ a manual feed tray screwed to a side of the apparatus main body as a manual paper feed unit. Meanwhile, a retractable manual feed tray attached rotatably to the apparatus main body so as to be openable and closable in consideration of space savings and appearance is also employed in many conventional image forming apparatuses.
This retractable manual feed tray stands against a side of the apparatus main body when retracted (closed). In this state, no paper is feedable. However, this does not pose a problem in many cases. This is because the manual feed tray is used to feed paper mostly when specialty paper such as postcards, OHP sheets, and sticker sheets is used, and such specialty paper is used less frequently than plain paper except for some users and it is often the case that only a single copy is made.
Further, for instance, Japanese Laid-Open Utility Model Application No. 4-12425 discloses a paper feed unit into which a paper feed cassette and a manual feed unit are integrated. The paper feed cassette is capable of carrying (containing) a stack of paper sheets as the paper feed cassette of the automatic paper feed unit. The manual feed unit, to which paper sheets are fitted and fed manually one by one, is mounted integrally on the upper surface of the paper feed cassette. In principle, plain paper is contained in the cassette to be fed, and heavy paper is fed from the manual feed unit. However, the side fences of the manual feed unit project upward on the upper surface of the cassette, so that the paper feed unit cannot be retracted as a retractable manual feed tray.